We have heard that soy can have an affect on female fertility, but can soy affect male fertility also? Researchers at the Harvard School for Public Health in Boston say so.

In a study released by the School, it was reported that those who eat just a half a serving of soy per day may have a 40% decrease in sperm production. That can have a devastating effect on men who already suffer with lower-than-normal sperm production.

So, what is the problem with soy – something that is generally touted as being very healthy for you? It contains isoflavins which contain phytoestrogens, or estrogen-like substances that can confuse the body and make it think there is too much estrogen in the system. This is what causes a decrease in sperm production; even affecting sperm quality. Basically, the report explains, soy causing interference with hormone signals and this can decrease both male and female fertility.

For instance, the six-year Harvard study indicated that men who ate just a half serving of soy only released 65 million sperm in their semen, compared to non-soy-eating participants who averaged 120 million sperm per sample. That is a dramatic decrease that can not be overlooked, say the experts. Still others disagree, saying that even 65 million sperm is enough to impregnate a partner. That is true, but, say critics, what about men who already have a decreased sperm production level? Cutting their sperm production by another 40-50% could make them totally infertile.

Some researchers have gone so far as to say that soy is “feminizing” today’s male, although many disagree, stating that an increase in this estrogen-mimicking chemical may affect sperm counts, but nothing else in regards to their “maleness.”

Women too can be affected by soy products, since it can boost their estrogen levels even higher, playing havoc with other fertility hormones in the body. Ovulation and conception require a balance of hormones in the body at certain times of the month, and having too much estrogen can throw off the entire process.

Now, if you are not a vegetarian or do not often eat soy products, you may think that you are safe from this fertility-killer. Not necessarily. Soy is hidden in a lot of our foods without us ever realizing it. For instance, most power drinks, protein powders, breads, power bars, nutritional bars and other foodstuffs contain high levels of soy. Drinking just a few ounces of one of these soy-based drinks every day could have a detrimental effect on both you and your partners overall ability to conceive a child and should be considered.

Another thing to consider is that most soy grown in the USA is genetically modified, GMO foods have also been shown to have negative effects on fertility.

For those who have been trying to get pregnant to no avail, a good look at both of your soy levels could be the answer. The good news is that soy does not seem to cause any lasting fertility damage. Luckily, by taking the soy out of your diet, you can boost sperm levels within a few months, making a pregnancy more likely.

References:
– Chavarro, J., Toth, T., Sadio, S., and Hauser, R. (Nov. 2008). Soy food and isoflavone intake in relation to semen quality parameters among men from an infertility clinic. Hum. Reprod. DOI: 10.1093/humrep/den243 Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2721724/